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New Linux Kernel Crash-Exploit discovered
Ant writes " According to linuxreviews article's on 6/11/2004, there is a nasty bug that lets a simple C program crash the kernel (2.4.18-2.6.x reported so far), effectively locking the whole system. Affects both 2.4.2x and 2.6.x kernels on the x86 architecture. This exploit can be compiled and run without a root access and with a shell access. There are detailed information and source code mentioned. " You need to have shell access to run this program; it's also worth noting that not *all* flavors are vulnerable. Please read article for the full details.
It doesn't require external programs in order to crash.
Gnusay -- for all your talking gnu needs.
is to buy a mac and run yellow dog on it!
/ducks
you want us to "read" the article and not jump headfirst into an open source vs. closed source flamewar??? :P
#include <stdio.h>
int main(void)
{
printf("I love Windows\n");
return (0);
}
Gentlemen, the time has come for a serious discussion on whether or not to continue using C for serious programming projects. As I will explain, I feel that C needs to be retired, much the same way that Fortran, Cobol and Perl have been. Furthermore, allow me to be so bold as to suggest a superior replacement to this outdated language.
To give you a little background on this subject, I was recently asked to develop a client/server project on a Unix platform for a Fortune 500 company. While I've never coded in C before I have coded in VB for fifteen years, and in Java for over ten, I was stunned to see how poorly C fared compared to these two, more low-level languages.
C's biggest difficulty, as we all know, is the fact that it is by far one of the slowest languages in existance, especially when compared to more modern languages such as Java and C#. Although the reasons for this are varied, the main reasons seems to be the way C requires a programmer to laboriously work with chunks of memory.
Requiring a programmer to manipulate blocks of memory is a tedious way to program. This was satisfactory back in the early days of coding, but then again, so were punchcards. By using what are called "pointers" a C programmer is basically requiring the computer to do three sets of work rather than one. The first time requires the computer to duplicate whatever is stored in the memory space "pointed to" by the pointer. The second time requires it to perform the needed operation on this space. Finally the computer must delete the duplicate set and set the values of the original accordingly.
Clearly this is a horrendous use of resources and the chief reason why C is so slow. When one looks at a more modern (and a more serious) programming language like Java, C# or - even better - Visual Basic that lacks such archaic coding styles, one will also note a serious speed increase over C.
So what does this mean for the programming community? I think clearly that C needs to be abandonded. There are two candidates that would be a suitable replacement for it. Those are Java and Visual Basic.
Having programmed in both for many years, I believe that VB has the edge. Not only is it slightly faster than Java its also much easier to code in. I found C to be confusing, frightening and intimidating with its non-GUI-based coding style. Furthermore, I like to see the source code of the projects I work with. Java's source seems to be under the monopolistic thumb of Sun much the way that GCC is obscured from us by the marketing people at the FSF. Microsoft's "shared source" under which Visual Basic is released definately seems to be the most fair and reasonable of all the licenses in existance, with none of the harsh restrictions of the BSD license. It also lacks the GPLs requirement that anything coded with its tools becomes property of the
FSF.
I hope to see a switch from C to VB very soon. I've already spoken with various luminaries in the C coding world and most are eager to begin to transition. Having just gotten off the phone with Mr. Alan Cox, I can say that he is quite thrilled with the speed increases that will occur when the Linux kernel is completely rewritten in Visual
Basic. Richard Stallman plans to support this, and hopes that the great Swede himself, Linux Torvaldis, won't object to renaming Linux to VB/Linux. Although not a C coder himself, I'm told that Slashdot's very own Admiral Taco will support this on his web site. Finally,
Dennis Ritchie is excited about the switch!
Thank you for your time. Happy coding.
Let's just hope they're not browsing for pr0n.
How many systems deployed in real world enviorments give anyone other then IT staff shell access?
DeviantArt Page
NSFW...having programmed in VB for the last 8 years doing kernel level programming...
I think you'll need to clarify that for us slashdot folk.
I thought Monday's were supposed to be Windows patch days, Tuesdays were for Linux, Wednesday was Apache, Thursday was Windows again, Friday was SSH...
Your sysadmin needs this advice:
If your system is a production server with 1000 on line users then do not test this code on that box.
Slashdot blurb about Windows bug
Linux trolls: Windows sucks!!!
Slashdot blurb about Linux bug
Linux trolls: Windows sucks!!!
Martin
FTFA (From The Fine Article):
``This doesn't affect NetBSD Stable.''
The exploit code also doesn't work on Windows 95, nor on Menuet. I haven't tested SkyOS, because I don't have a license.
Please correct me if I got my facts wrong.
How do we blame Micro$oft for this?
I've come up with the final word in firewall technology. What I do is connect my PC to the DSL router with a 10' ethernet cable. Then, using an approved tool, I carefully cut the cable, making sure to sever it completely. Haven't had a problem since.
What we really need is an article suggesting how I can speed up my downloads...
Of course you realise that by doing that you are violating several patents on "Air Gap Firewall Technology".
#include
#include
#include
static void Handler(int ignore)
{
char fpubuf[108];
write(2, "*", 1);
}
int main(int argc, char *argv[])
{
struct itimerval spec;
signal(SIGALRM, Handler);
spec.it_interval.tv_sec=0;
spec.it_interval.tv_usec=100;
spec.it_value.tv_sec=0;
spec.it_value.tv_usec=100;
setitimer(ITIMER_REAL, &spec, NULL);
while(1)
write(1, ".", 1);
return 0;
}
by simply commenting out the inline assembly, i fixed crash.c so it can no longer crash Linux!
1 2 1 2 THE NAKEN CREW
How am I supposed to keep up with this stuff?
My beliefs do not require that you agree with them.
This is a common mistake that many first-time security administrators make. You're supposed to cut the cable before making the PC/router connection -- always implement your security protocol before connecting equipment to the outside world.
Your downloads are probably slow because your machine was compromised during the time when your security was down - i.e., the interval between connecting the unsecured cable and the time you properly locked the connection down. Slow downloads are a key sign of a compromised system.
Once you suspect your machine's been compromised, there's really no safe solution other than reinstalling everything from scratch. I'd also suggest discarding the cable and getting a new one - since you didn't secure the cable first, there may be an RF resonance bug lurking on the PC half of the cable, waiting to reinfect your machine when you hook it back up.
You're obviously new to this, so just in case you haven't heard about them - RF resonance bugs use the reflection characteristics of an Ethernet cable to create a self-reinforcing standing-wave signal containing a copy of the virus. Older versions of these bugs could be dealt with simply by putting the cable in a Faraday cage and grounding the cable. But several of the more current RF resonator bugs contain quantum-mechanical sideband waveforms - put one of those in a Faraday cage and the q-m sidebands can refractively propogate into the cage itself, and you'll spend the rest of the day chasing down heisenbugs.
Anyways, don't feel bad about this - it's a common enough mistake when you're just getting started with security. And by posting on /. you may have helped several other novices avoid making the same mistake.
A marriage is always made up of two people who are prepared to swear that only the other one snores.